Filter no reflow during percutaneous coronary interventions using the Filterwire distal protection device

The combination assessment of lipid pool and thrombus by optical coherence tomography can predict the filter no-reflow in primary PCI for ST elevated myocardial infarction

The usefulness of distal protection devices is still controversial. Moreover, there is no report on thrombus evaluation by using optical coherence tomography (OCT) for determining whether to use a distal protection device. The aim of the present study was to investigate the predictor of filter no-reflow (FNR) by using OCT in primary percutaneous coronary intervention (PCI) for ST-elevated acute myocardial infarction (STEMI).We performed preinterventional OCT in 25 patients with STEMI who were undergoing primary PCI with Filtrap. FNR was defined as coronary flow decreasing to TIMI flow grade 0 after mechanical dilatation.FNR was observed in 13 cases (52%). In the comparisons between cases with or without the FNR, the stent length, lipid pool length, lipid pool + thrombus length, and lipid pool + thrombus index showed significant differences. In multivariate analysis, lipid pool + thrombus length was the only independent predictor of FNR (OR 1.438, 95% CI 1.001 - 2.064, P < .05). The optimal cut-off value of lipid pool + thrombus length for predicting FNR was 13.1 mm (AUC = 0.840, sensitivity 76.9%, specificity 75.0%). Moreover, when adding the evaluation of thrombus length to that of lipid pool length, the prediction accuracy of FNR further increased (IDI 0.14: 0.019-0.25, P = .023).The longitudinal length of the lipid pool plus thrombus was an independent predictor of FNR and the prediction accuracy improved by adding the thrombus to the lipid pool. These results might be useful for making intraoperative judgment about whether filter devices should be applied in primary PCI for STEMI.

Endovascular Rescue of a Fused Monorail Balloon and Cerebral Protection Device

Purpose:

To present a case of successful endovascular retrieval of a monorail predilation balloon fused to an embolic protection device (EPD) in the distal internal carotid artery (ICA) of a high-risk symptomatic patient.

Case Report:

A 60-year-old man with documented systemic atherosclerotic disease had a severe (>70%) restenosis in the left ICA 3 years after endarterectomy. He was scheduled for carotid artery stenting (CAS) with cerebral protection; however, he developed unstable angina and was transferred to our facility, where the admitting team decided that staged CAS followed by coronary bypass grafting would be the best option. During the CAS procedure, a 6-mm AccuNet filter was passed across the lesion via a 6-F carotid sheath and deployed in the distal ICA without incident. However, the 4-×20-mm predilation monorail balloon was then advanced without visualizing the markers, resulting in inadvertent aggressive interaction that trapped the balloon's tip in the filter. Several maneuvers to separate the devices were unsuccessful. Finally, the filter/balloon combination was moved gently retrograde until the balloon was straddling the subtotal ICA lesion. The lesion was dilated to 4 mm with the balloon, and the sheath was gently advanced across the lesion as the balloon was deflated. Angiography excluded interval occlusion of the filter from the embolic debris during the aforementioned aggressive maneuvers and documented antegrade flow. The filter was slowly withdrawn into the 6-F sheath with simultaneous aspiration. A second 6-mm filter was deployed, and the procedure was completed satisfactorily. The patient did well, with no neurological sequelae.

Conclusion:

EPDs are an essential in carotid artery stenting and, keeping in mind the potential risks associated with their use, will help the operator avoid complications such as this one.

A combination of plaque components analyzed by integrated backscatter intravascular ultrasound and serum pregnancy-associated plasma protein a levels predict the no-reflow phenomenon during percutaneous coronary intervention

AIMS

Previous studies reported that integrated backscatter intravascular ultrasound (IB-IVUS) provides high diagnostic accuracy for tissue characterization of coronary plaques and that pregnancy-associated plasma protein A (PAPP-A) could be a marker of adverse cardiac outcome in patients with cardiovascular disease. We examined whether IB-IVUS and PAPP-A levels could predict the incidence of no-reflow during percutaneous coronary intervention (PCI) METHODS AND RESULTS: About 176 consecutive patients (138 men, mean age 68 ± 11 years) who underwent PCI with IB-IVUS were prospectively enrolled. Combined no-reflow, including transient filter no-reflow by using distal protection devices, was observed in 31 patients. The percentages of coronary lipid volume (%LV) analyzed by IB-IVUS and serum PAPP-A were significantly higher in patients with combined no-reflow than normal-reflow. To predict no-reflow, a receiver operating characteristic (ROC) analysis determined cut-off values of %LV as 62% and serum PAPP-A as 7.71 ng/mL. The multivariate logistic regression analysis showed that %LV (hazard ratio 4.5, 95% confidence interval 1.6-13.4, P < 0.01) and PAPP-A (hazard ratio 4.32, 95% confidence interval 1.5-12.7, P < 0.01) were independent predictors of combined no-reflow

CONCLUSIONS

%LV analyzed by IB-IVUS and serum PAPP-A levels were closely associated with the coronary no-reflow phenomenon. © 2014 Wiley Periodicals, Inc.

No-reflow phenomenon: pathophysiology, diagnosis, prevention, and treatment. A review of the current literature and future perspectives

No-reflow is responsible for 40% of the primary percutaneous coronary intervention without complete myocardial reperfusion despite successful reopening of the infarct-related artery. This review describes the main pathophysiological mechanisms of no-reflow, its clinical manifestation, including the strong association with increased in-hospital mortality, malignant arrhythmias, and cardiac failure as well as the diagnostic methods. The latter ranges from simple angiographic thrombolysis in myocardial infarction grade score to more complex angiographic indexes, imaging techniques such as myocardial contrast echo or cardiac magnetic resonance, and surrogate clinical end points such as ST-segment resolution. This review also summarizes the strategies of prevention and treatment of no-reflow, considering the most recent studies results regarding medical therapy and devices.

Case-control registry of excimer laser coronary angioplasty versus distal protection devices in patients with acute coronary syndromes due to saphenous vein graft disease

Laser atherectomy might decrease procedural complications during percutaneous coronary intervention (PCI) of degenerated saphenous vein grafts (SVGs) in case of unstable or thrombotic lesions because of its ability to debulk and vaporize thrombus. We aimed at prospectively evaluating the safety and efficacy of excimer laser coronary angioplasty (ELCA) as a primary treatment strategy in consecutively unstable patients undergoing PCI of degenerated SVG lesions. Seventy-one consecutive patients with non-ST elevation acute coronary syndrome (mean age 69 ± 10 years, 66 men [89%]) undergoing PCI of degenerated SVG were enrolled in a prospective case-control registry, using 2 different distal protection devices (DPDs; FilterWire EZ [Boston Scientific, Natick, Massachusetts; n = 24] and SpiderRX [Ev3, Plymouth, Minnesota; n = 23]) or ELCA (n = 24). Primary end points of the study were incidence of angiographic microvascular obstruction (Thrombolysis In Myocardial Infarction flow grade of <3 or Thrombolysis In Myocardial Infraction flow grade of 3 with myocardial blush grade 1 to 2) and incidence of type IVa myocardial infarction. Angiographic microvascular obstruction incidence tended to be less in ELCA-treated patients compared with DPD-treated patients (3 [13%] vs 15 [32%], p = 0.09). Type IVa myocardial infarction incidence was more in DPD-treated patients compared with ELCA-treated patients (23 [49%] vs 5 [21%], p = 0.04). In conclusion, in patients with non-ST elevation acute coronary syndrome undergoing PCI of degenerated SVG, ELCA compared with DPD, is associated with a trend for better myocardial reperfusion and a lesser incidence of periprocedural necrosis. Controlled randomized trials are warranted to confirm these early observations.

Prediction of distal embolization during percutaneous coronary intervention for unstable plaques with grayscale and integrated backscatter intravascular ultrasound

OBJECTIVES

We performed microscopic examination of the debris collected by a distal protection device and investigated the usefulness of grayscale and integrated backscatter intravascular ultrasound (IB-IVUS) for the prediction of distal embolization during percutaneous coronary intervention (PCI) in cases of unstable angina.

BACKGROUND

The prediction of distal embolization during PCI has not been studied in depth because assessment of distal embolization is difficult.

METHODS

We prospectively studied 39 consecutive patients with unstable angina who underwent PCI with a filter distal protection device. The preprocedural plaque volume at target lesions was measured with grayscale IVUS and plaque characteristics were assessed with IB-IVUS. We performed microscopic examination of the particles collected by the distal protection device.

RESULTS

There was a significant correlation between the plaque volume and the number of the collected particles >100 μm in diameter (r = 0.48, P = 0.0034). Filter no-reflow (FNR) phenomenon was found in nine patients. The plaque volume was significantly greater (355 ± 133 mm(3) vs. 199 ± 90 mm(3) , P = 0.0004), and the lipid ratio was significantly higher (29.3 ± 4.3% vs. 26.1 ± 4.3 P = 0.045) in the FNR group compared with the non-FNR group. Multivariate logistic regression analysis showed that the plaque volume was an independent predictor of FNR phenomenon.

CONCLUSIONS

Although tissue characterization of IB-IVUS may provide additional information for distal embolization, plaque volume is the only significant predictor of distal embolization during PCI.

Management of the no-reflow phenomenon

The lack of reperfusion of myocardium after prolonged ischaemia that may occur despite opening of the infarct-related artery is termed "no reflow". No reflow or slow flow occurs in 3-4% of all percutaneous coronary interventions, and is most common after emergency revascularization for acute myocardial infarction. In this setting no reflow is reported to occur in 30% to 40% of interventions when defined by myocardial perfusion techniques such as myocardial contrast echocardiography. No reflow is clinically important as it is independently associated with increased occurrence of malignant arrhythmias, cardiac failure, as well as in-hospital and long-term mortality. Previously the no-reflow phenomenon has been difficult to treat effectively, but recent advances in the understanding of the pathophysiology of no reflow have led to several novel treatment strategies. These include prophylactic use of vasodilator therapies, mechanical devices, ischaemic postconditioning and potent platelet inhibitors. As no reflow is a multifactorial process, a combination of these treatments is more likely to be effective than any of these alone. In this review we discuss the pathophysiology of no reflow and present the numerous recent advances in therapy for this important clinical problem.

Manual aspiration prior to stenting does not reduce the incidence of filter no reflow in saphenous vein graft lesions protected by FilterWire EX/EZ

BACKGROUND

The beneficial role of manual thrombus aspiration in thrombus-containing lesions has been proven in acute myocardial infarction but data is lacking in saphenous vein graft lesions.

METHODS

From January 2004 to December 2008, 74 consecutive post-bypass patients underwent percutaneous coronary interventions to 76 saphenous vein graft lesions under the protection of FilterWire EX/EZ. Among them, the latest 25 consecutive patients with 25 lesions were treated with manual aspiration before stenting. The incidence of filter no reflow was compared between patients with and without manual aspiration pretreatment.

RESULTS

No major difference in demography, clinical, lesion, and procedure characteristics, and in-hospital outcome has been observed between the two patient groups. Most importantly, the incidence of filter no reflow has not been reduced (32.0% versus 19.6%, P = 0.26) by manual aspiration, even among thrombus-containing lesions (63.2% versus 64.7%, P = 1.00). The absence of diabetes mellitus is found to be the independent predictor for the occurrence of filter no reflow.

CONCLUSIONS

Adjunctive manual thrombus aspiration fails to reduce the filter no reflow, and probably has no additional benefit in saphenous vein graft lesions already protected by FilterWire EX/EZ.

Initial clinical experience with distal embolic protection using "Filtrap", a novel filter device with a self-expandable spiral basket in patients undergoing percutaneous coronary intervention

We developed a new filter-type distal protection guide wire, Filtrap, that uses a polyurethane filter with 1834 100-μm micropores covering the distal half of a spindle-shaped spiral Ni-Ti basket. The basket is 5 mm in diameter, self-expandable, and is mounted at the distal end of the system. This study aimed to assess the usefulness and safety of Filtrap during percutaneous coronary intervention (PCI). Early angiographic and in-hospital outcomes were reviewed in 14 patients, including 9 acute coronary syndrome patients, treated with Filtrap during PCI. All lesions were located in native coronary arteries but one was located in a saphenous vein graft. The Filtrap was successfully delivered and deployed distal to the lesion in 13 of 14 patients (93%). All PCI procedures including stent implantation were successfully completed except for 2 AMI patients, who ended up with Thrombolysis in Myocardial Infarction (TIMI) 2 coronary flow. One of these 2 patients had a distal embolization which occurred after thrombectomy before Filtrap insertion. The mean time of device insertion was 9.4 ± 3.2 min. Five patients showed transient no-reflow that was completely restored immediately with removal of the device. Embolic debris was entrapped in 8 (62%) of these cases. All patients were free from in-hospital events except for one patient with a large anterior acute myocardial infarction who received an emergency surgery due to a free wall cardiac rupture. These results suggest that the Filtrap is a practical and safe device for embolic protection during PCI.

Adjunctive devices in primary or rescue PCI: a meta-analysis of randomized trials

OBJECTIVES

To overview and summarize the results emerging from the studies on adjunctive devices (AD) with theoretical anti-embolic properties in patients with ST-elevation acute myocardial infarction (STEMI) undergoing percutaneous coronary interventions (PCI).

BACKGROUND

A series of small-to-medium size randomized studies have compared different AD with standard PCI (SP) in the setting of STEMI. The reported results are conflicting.

METHODS

Eighteen prospective randomized studies on 3180 STEMI patients comparing AD with SP were identified and entered the meta-analysis. Pre-specified angiographic, electrocardiographic (absence of ST-segment resolution, STR) and early (up to 30 days) clinical end-points were assessed.

RESULTS

AD were associated with lower rates of angiographically evident distal embolization: OR (95% CI): 0.54 (0.37-0.81). Analyses of angiographic and electrocardiographic reperfusion showed striking heterogeneity among studies and an overall trend toward better results with AD: OR (95% CI) 0.76 (95% CI 0.51-1.12) for TIMI<3, 0.53 (0.37-0.76) for myocardial blush grade (MBG)<3, 0.60 (0.45-0.78) for absence of STR. Subgroup analysis according to the type of AD for the end-point of no STR showed concordant absence of benefit in studies testing distal protection devices, positive results being confined to the studies using thrombectomy devices (OR 0.46, 95% CI 0.32-0.66). However, the possibility of a "small study" bias within thrombectomy studies cannot be discharged (significant heterogeneity and positive Egger's test). Early major adverse cardiac events were not different between AD and SP.

CONCLUSIONS

AD use may be associated with reduced rate of angiographic distal embolization, and improved MBG 3 and STR rates. However, efficacy might vary with the type of device employed. Moreover, early clinical outcome is not modified suggesting that further, larger, studies are needed to assess the clinical impact of AD.

CONDENSED ABSTRACT

We conducted a meta-analysis of 18 prospective randomized trials comparing adjunctive devices (AD) with standard PCI in the setting of STEMI. The use of AD was associated with lower rates of (angiographically evident) distal embolization. Analyses of angiographic and electrocardiographic reperfusion showed striking heterogeneity and an overall trend toward better results with AD. Subgroup analysis suggested that different types of device may have different effects. Early major adverse cardiac events were similar between AD and SP.

Particulate debris collected during carotid stenting: are we missing something?

Particulate and histopathologic examination of atherosclerotic material collected during carotid artery stenting is presented, illustrating the limitations of current knowledge regarding the use of distal protection devices (DPD) during this novel vascular intervention.

Plaque volume and occurrence and location of periprocedural myocardial necrosis after percutaneous coronary intervention: insights from delayed-enhancement magnetic resonance imaging, thrombolysis in myocardial infarction myocardial perfusion grade analysis, and intravascular ultrasound

BACKGROUND

Myocardial necrosis can occur during percutaneous coronary intervention (PCI) despite optimal adjunctive pharmacology and careful technique. We investigated the mechanisms of procedural infarction using angiographic analysis, intravascular ultrasound, and delayed-enhancement magnetic resonance imaging.

METHODS AND RESULTS

Fifty-two patients (64 vessels) who underwent complex PCI were studied. All patients were preloaded with clopidogrel and received glycoprotein IIb/IIIa inhibitors. "Adjacent" myonecrosis was defined as the presence of an area of new gadolinium hyperenhancement close to the stent. "Distal" myonecrosis was defined as situated at least 10 mm downstream from the stent. Fifteen vessels (23%) had evidence of new hyperenhancement after PCI. Of these, 8 (12%) had the distal type, and 7 (11%) had the adjacent type. Intravascular ultrasound showed a significantly greater reduction in plaque volume (91.6+/-51.5 versus 8+/-14 versus 20+/-35 mm3; P < 0.001) in the group with distal hyperenhancement compared with patients without new hyperenhancement or adjacent hyperenhancement. In the entire sample, a significant correlation was seen between changes in plaque volume (rho = 0.58, P < 0.001) after PCI and the mass of new necrosis measured by magnetic resonance imaging. Thrombolysis in Myocardial Infarction perfusion grade assessment of a closed microvasculature after PCI carried an odds ratio of 8.0 (95% confidence interval, 1.4 to 46.1; P = 0.02) for the occurrence of hyperenhancement, whereas side-branch occlusion was associated with an odds ratio of 16.2 (95% confidence interval, 2.6 to 102.5; P = 0.03). However, a closed microvasculature was associated with distal hyperenhancement (P = 0.02), and side-branch occlusion was associated with adjacent hyperenhancement (P < 0.001).

CONCLUSIONS

These data suggest that distal embolization of plaque material occurs in contemporary PCI of native coronary arteries. Efforts to minimize procedural necrosis may require careful review of side branch anatomy and/or use of distal protection during extensive coronary stenting.